1. Field of the Invention
The present invention relates generally to an apparatus and method for receiving broadcasting service information in a digital broadcasting system, and in particular, to an apparatus and method for receiving Program Specific Information (PSI) and Service Information (SI) in a Digital Video Broadcasting-Handheld (DVB-H) receiver.
2. Description of the Related Art
Typically, broadcasting services target all users with broadcasting terminals. The broadcasting services are categorized into a audio broadcasting service that broadcasts voice only, such as radio broadcasting, video-focused broadcasting service like TV broadcasting, and a multimedia broadcasting service that includes audio, video and data. Starting with analog, these broadcasting services are moving to digital transmission owing to drastic technological development. Provisioning of the broadcasting services has evolved from transmission from transmitting towers to transmission of high-image quality, high-speed multimedia data via cable over a wired network, by satellites, or in both.
One of such broadcasting technologies is Digital Multimedia Broadcasting (DMB) that has fully entered a commercialization stage. Springing from Digital Audio Broadcasting (DAB), DMB is based on the European Research Coordination Agency project (Eureka)-147 standard of DAB.
The source of the DAB technology, Europe has organized a standard-specifying body called DVB and is working on standardization of mobile broadcasting under the name “DVB-H”. DVB-H is a new standard that the European digital TV broadcasting standardization group DAB is developing after DVB-Satellite (DVB-S), DVB-Cable (DVB-C), and DVB-Terrestrial (DVB-T).
The DVB group, which previously focused on the development of DVB-eXtension (DVB-X), shifted gears in search of a new broadcasting paradigm DVB-H that makes the concept of mobile broadcasting apparent, considering that 3rd Generation (3G) mobile communication technologies such as Universal Mobile Telecommunication System (UMTS) and International Mobile Telecommunication-2000 (IMT-2000), terrestrial digital TV, and DAB have limitations in providing a large volume of multimedia contents such as movies and broadcasting programs through mobile terminals.
DVB-H is a standard that enforces mobility to the European digital TV transmission standard, DVB-T. It is an extension from DVB-T, which supports low power, mobility, and portability in mobile terminals or portable image devices. Therefore, most of DVB-H physical layer standards were borrowed from DVB-T standards, except for several additional functionalities for portable/mobile reception.
A DVB-H system supports additional error correction coding for Layer 3 Internet Protocol (IP) packets. This is called Multi-Protocol Encapsulation-Forward Error Correction (MPE-FEC).
In the DVB-H system, broadcasting data are created in the form of IP datagrams. The IP datagrams are constructed to an MPE-FEC frame through Reed-Solomon (R-S) coding. Therefore, the MPE-FEC frame is divided into an MPE section with the IP datagrams and an MPE-FEC section with parity data generated from the R-S coding. The MPE and MPE-FEC sections are sent in a payload of a Transport Stream (TS) packet from a physical layer. The TS packet is a DVB-H transmission unit.
The above-described digital broadcasting system uses Motion Picture Experts Group (MPEG-2) TS.
The MPEG-2 TS system multiplexes audio and video data of broadcasting programs to 188-byte TS packets and gives a Packet IDentifier (PID) to the audio/video data of each broadcasting program. Upon receipt of the TS packets, a terminal identifies audio/video data by a PID and separates the audio/video data from the TS packets by filtering and demultiplexing. To allow the terminal to know the PIDs of audio/video data of the programs, information is sent to the terminal in the TS. A Program Map Table (PMT) lists the PIDs of audio/video data of the broadcasting programs. Since the PMT is also delivered in a TS packet, a PID identifies it. This PMT PID is known from a Program Association Table (PAT).
To view digital broadcasting services including DMB, the terminal acquires the PMT PIDs of broadcasting programs from an initial PAT. When the user of the terminal selects a broadcasting program, the terminal acquires a PMT by the PMT PID of the broadcasting program. The PMT includes the PID of audio/video TS packets of the selected broadcasting program. The PAT, PMT, and other information form PSI, which is defined as a part of the MPEG-2 TS system.
Aside from the PSI, information about the broadcasting programs is delivered in SI. Major SI information is an Electronic Program Guide (EPG). The EPG is carried in packets, Event Information Table (EIT), Service Description Table (SDT), and Time Offset Table (TOT).
In the present invention, both the PSI and the SI are called broadcasting service information.
Existing digital broadcasting systems including DMB regulate that the PSI and the SI are delivered in TS packets and have their own PIDs. The terminal acquires the PSI and the SI from received TS packets using the PIDs.
As stated above, major information delivered in PSI and SI packets is an EPG In other words, channel information is sent in the PSI and the SI. Hence, a terminal in the conventional digital broadcasting systems acquires the EPG from the PSI and SI.
However, since the DVB-H system adopts a transmission scheme of sending the EPG in IP datagrams, the DVB-H receiver does not need to receive the EIT, SDT and TOT of the PSI and SI. Conventionally, a broadcasting terminal is supposed to receive all PSI and SI packets and generate an interrupt signal to send the PSI and SI packets to a host. Consequently, the reception of unnecessary PSI and SI packets causes overhead.
That is, upon receipt of a predetermined number of TSs, a hardware logic sends them to the host without filtering of a PSI/SI PID, generating an interrupt signal. The host stores a large number of (hundreds to thousands of) packets in frames in a large-capacity system memory and returns selected packets with a PSI/SI PID to an application processor. While a hardware logic memory may have a small capacity, the capacity requirement of the system memory of the host increases. Moreover, unnecessary PSI/SI packets are sent to the host. Hence, frequent interrupt generation and filtering increase overhead.
Accordingly, there exists a need for a technique for reducing the overhead and efficiently sending PSI/SI to the host. However, no techniques associated with transmission of PSI/SI from the DVB-H receiver to the host have been specified yet.